1 /* 2 * Copyright (c) 1980, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)param.c 8.3 (Berkeley) 8/20/94 35 * $FreeBSD: src/sys/kern/subr_param.c,v 1.42.2.10 2002/03/09 21:05:47 silby Exp $ 36 * $DragonFly: src/sys/kern/subr_param.c,v 1.7 2005/06/26 22:03:22 dillon Exp $ 37 */ 38 39 #include "opt_param.h" 40 #include "opt_maxusers.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/malloc.h> 46 #include <vm/pmap.h> 47 #include <machine/vmparam.h> 48 49 /* 50 * System parameter formulae. 51 */ 52 53 #ifndef HZ 54 #define HZ 100 55 #endif 56 #define NPROC (20 + 16 * maxusers) 57 #ifndef NBUF 58 #define NBUF 0 59 #endif 60 #ifndef MAXFILES 61 #define MAXFILES (maxproc * 16) 62 #endif 63 #ifndef MAXPOSIXLOCKSPERUID 64 #define MAXPOSIXLOCKSPERUID (maxusers * 64) /* Should be a safe value */ 65 #endif 66 67 int hz; 68 int stathz; 69 int profhz; 70 int ustick; /* tick interval in microseconds */ 71 int nstick; /* tick interval in nanoseconds */ 72 int maxusers; /* base tunable */ 73 int maxproc; /* maximum # of processes */ 74 int maxprocperuid; /* max # of procs per user */ 75 int maxfiles; /* system wide open files limit */ 76 int maxfilesrootres; /* descriptors reserved for root use */ 77 int minfilesperproc; /* per-proc min open files (safety) */ 78 int maxfilesperproc; /* per-proc open files limit */ 79 int maxfilesperuser; /* per-user open files limit */ 80 int maxposixlocksperuid; /* max # POSIX locks per uid */ 81 int ncallout; /* maximum # of timer events */ 82 int mbuf_wait = 32; /* mbuf sleep time in ticks */ 83 long nbuf; 84 long nswbuf; 85 long maxswzone; /* max swmeta KVA storage */ 86 long maxbcache; /* max buffer cache KVA storage */ 87 int vmm_guest = 0; /* Running as virtual machine guest? */ 88 u_quad_t maxtsiz; /* max text size */ 89 u_quad_t dfldsiz; /* initial data size limit */ 90 u_quad_t maxdsiz; /* max data size */ 91 u_quad_t dflssiz; /* initial stack size limit */ 92 u_quad_t maxssiz; /* max stack size */ 93 u_quad_t sgrowsiz; /* amount to grow stack */ 94 95 /* 96 * These have to be allocated somewhere; allocating 97 * them here forces loader errors if this file is omitted 98 * (if they've been externed everywhere else; hah!). 99 */ 100 struct buf *swbuf; 101 102 /* 103 * Boot time overrides that are not scaled against main memory 104 */ 105 void 106 init_param1(void) 107 { 108 hz = HZ; 109 TUNABLE_INT_FETCH("kern.hz", &hz); 110 stathz = hz * 128 / 100; 111 profhz = stathz; 112 ustick = 1000000 / hz; 113 nstick = 1000000000 / hz; 114 /* can adjust 30ms in 60s */ 115 ntp_default_tick_delta = howmany(30000000, 60 * hz); 116 117 #ifdef VM_SWZONE_SIZE_MAX 118 maxswzone = VM_SWZONE_SIZE_MAX; 119 #endif 120 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone); 121 #ifdef VM_BCACHE_SIZE_MAX 122 maxbcache = VM_BCACHE_SIZE_MAX; 123 #endif 124 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache); 125 maxtsiz = MAXTSIZ; 126 TUNABLE_QUAD_FETCH("kern.maxtsiz", &maxtsiz); 127 dfldsiz = DFLDSIZ; 128 TUNABLE_QUAD_FETCH("kern.dfldsiz", &dfldsiz); 129 maxdsiz = MAXDSIZ; 130 TUNABLE_QUAD_FETCH("kern.maxdsiz", &maxdsiz); 131 dflssiz = DFLSSIZ; 132 TUNABLE_QUAD_FETCH("kern.dflssiz", &dflssiz); 133 maxssiz = MAXSSIZ; 134 TUNABLE_QUAD_FETCH("kern.maxssiz", &maxssiz); 135 sgrowsiz = SGROWSIZ; 136 TUNABLE_QUAD_FETCH("kern.sgrowsiz", &sgrowsiz); 137 } 138 139 /* 140 * Boot time overrides that are scaled against main memory 141 */ 142 void 143 init_param2(int physpages) 144 { 145 size_t limsize; 146 147 /* 148 * Calculate manually becaus the VM page queues / system is not set up yet 149 */ 150 limsize = (size_t)physpages * PAGE_SIZE; 151 if (limsize > KvaSize) 152 limsize = KvaSize; 153 limsize /= 1024 * 1024; /* smaller of KVM or physmem in MB */ 154 155 /* Base parameters */ 156 maxusers = MAXUSERS; 157 TUNABLE_INT_FETCH("kern.maxusers", &maxusers); 158 if (maxusers == 0) { 159 maxusers = limsize / 8; /* ~384 per 3G */ 160 if (maxusers < 32) 161 maxusers = 32; 162 /* no upper limit */ 163 } 164 165 /* 166 * The following can be overridden after boot via sysctl. Note: 167 * unless overriden, these macros are ultimately based on maxusers. 168 * 169 * Limit maxproc so that kmap entries cannot be exhausted by 170 * processes. 171 */ 172 maxproc = NPROC; 173 TUNABLE_INT_FETCH("kern.maxproc", &maxproc); 174 if (maxproc < 32) 175 maxproc = 32; 176 if (maxproc > limsize * 21) 177 maxproc = limsize * 21; 178 179 /* 180 * Maximum number of open files 181 */ 182 maxfiles = MAXFILES; 183 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); 184 if (maxfiles < 128) 185 maxfiles = 128; 186 187 /* 188 * Limit file descriptors so no single user can exhaust the 189 * system. 190 * 191 * WARNING: Do not set minfilesperproc too high or the user 192 * can exhaust the system with a combination of fork() 193 * and open(). Actual worst case is: 194 * 195 * (minfilesperproc * maxprocperuid) + maxfilesperuser 196 */ 197 maxprocperuid = maxproc / 4; 198 if (maxprocperuid < 128) 199 maxprocperuid = maxproc / 2; 200 minfilesperproc = 8; 201 maxfilesperproc = maxfiles / 4; 202 maxfilesperuser = maxfilesperproc * 2; 203 maxfilesrootres = maxfiles / 20; 204 205 /* 206 * Severe hack to try to prevent pipe() descriptors from 207 * blowing away kernel memory. 208 */ 209 if (KvaSize <= (vm_offset_t)(1536LL * 1024 * 1024) && 210 maxfilesperuser > 20000) { 211 maxfilesperuser = 20000; 212 } 213 214 maxposixlocksperuid = MAXPOSIXLOCKSPERUID; 215 TUNABLE_INT_FETCH("kern.maxposixlocksperuid", &maxposixlocksperuid); 216 217 /* 218 * Unless overriden, NBUF is typically 0 (auto-sized later). 219 */ 220 nbuf = NBUF; 221 TUNABLE_LONG_FETCH("kern.nbuf", &nbuf); 222 223 ncallout = 16 + maxproc + maxfiles; 224 TUNABLE_INT_FETCH("kern.ncallout", &ncallout); 225 } 226 227